Theodore guilleaume



(-No Model.) T. GUILLEAUMEJ -3 Sheets-Sheet 1.

I ELECTRIC CABLE. No. 554,263 Patented Feb. 11,1896.

(HoVModeU T" GUILLEEAUME. s Sheets-'-Shet 2.

ELEGTRIU GABLE- Patented Feb. 1.1, 1896.

I ImA nzo r;

(N0 Model.)

T. GUILLEAUME. 3Sheets-Sheet'3.

ELECTRIC CABLE.

No. 554,263. Patented Feb; 11, 1896.

"[1711 6306. v ,[n uen (or.

AN DREW EGRAHAM. PHOTO-H1110 WASHINTON. D C

'UNITED STATES PATENT OFFICE.

THEODORE GUILLEAUME, OF MllLllElM-ON-RIIINE, GERMANY.

ELECTRIC CABLE.

SPECIFICATION forming part of Letters Patent No. 554,263, dated February11, 1896.

Application filed March 19, 1895. Serial No. 542,375. (No model.)Patented in England November 1, 1893, No. 20,698,- in Belgium November10, 1893, No. 107,113,- in France November 11, 1893, No. 233,988; inAustria March 26, 1894,

No. 2,313, and in Hungary March 26, 1894, No. 1,112.

To all whom it may concern.-

Be it known that LTHEonoRE GUILLEAUME, a subject of the German Emperor,residing at Miilheim-on-Rhine, in the German Empire, have invented newand useful Improvements in and in Connection with Electric Oables, (inrespect whereof I have obtained or caused to be obtained Letters Patentin the following countries: Great Britain, dated November 1,1893,No. 20,698; Belgium,dated NovemberElO, 18-93, No. 107,113; France, datedNovember 11,1893, No.233,988; Austria,dated March 26, 1894:, No. 2,313,and Hungary, dated March 26, 1894, No. 1,112, and inrespect whereof Ihave applied for but have not yet obtained Letters Patent in Germany tobear date September 19, 1893,) of which the following is aspecification.

This invention relates to electric cables designed to obviate certaindifficulties attending the employment of electrical currents in placeswhere combustible substances or inflammable gases are present, one ofsuch difficulties being that in the event of the con ductor breaking thesparks emitted may cause ignition of the said substances or gases, andthus under certain circumstances-as, for eX- ample, in coal-mines-involmserious danger to life.

In a cable constructed according to this invention there is combinedwith the main conductor an additional or safety conductor made of lessductile metal than the main conductor. This safety-conductor serves, inconjunction with a switch device, to close the circuit whereby the mainconductor is connected with the source of electrical energy. Should themain conductor be strained to a point rendering fracture imminent, thesafety-conductor, owing to its inferior ductility, breaks, whereupon thecurrent passing through the same is interrupted, and the switch in themain circuit is opened. The current passing along that conductor is thusintercepted or diverted before fracture of the main conductor can takeplace.

The invention is also adapted to ghard against danger from sparkingshould the cable suffer injury by crushing.

In the accompanying drawings, Figure 1 representsin elevation a cableembodying a safety-conductor in accordance with this invention. Fig. 2is'a similar view of a cable provided with a safety-conductor andadapted to withstand external pressure or crushing. Fig. 3 illustratesthe method of connecting a cable such as represented in Fig. 1, Fig. 4-illustrating the method of connecting the cable shown in Fig. 2. Fig. 5illustrates the mode of combining a cable, such as Fig. 1, with asafety-switch, in order to provide against accidents which may ariseeither from excessive tension or from crushing. Fig. (5 is a sideelevation of a cable illustrating the mode of construction when two ormore safetyconductors in accordance with this invention are assembledtogether, Fig. 7 being a similar rent traversing the safety-conductor cis first interrupted in consequence of that conductor breaking, theeffect being that the main current is diverted from the principalconductor a before the latter breaks.

Where there is reason to apprehend crushing, the cable may beconstructed as illustrated in Fig. 2. In this instance thesafetyconductor 0 c, in the form of a bipart steel tape, is wound roundthe insulated copper conductor a in a coarse pitch double spiral. \Vheresuch a cable is liable to damage from concussion or crushing only (asdistinguished from excessive tension) the main and safety conductors mayrespectively be made of metal of equal ductility; but when it is desiredto provide in addition against the effect of tension thesafety-cowluctor composed of metal having less ductility than thatpossessed by the main conductor.

The above-described. arrangement may be adopted in connection withcables composed of several conductors, in which case the cable must beprovided with at least two safetyconductors. These latter may assume theform of a pair of conductors in the center of the cable, as shown in.Fig. 1, or as indicated in Fig. 3, but the most advantageous arrangementof the safety-conductors is shown in Figs. 0 and 7, where one of thesafety-conductors, c, is in the center of the cable, while the other, e,in the form of a metallic tape, may occupy a position cit-her betweenthe inner main conductor, a, and the outer main conductor, a, Fig. 6, orbetween the outer main conductor, a, and the lead covering 6, Fig. 7.

The method of connecting a cable such as described with reference toFig. 1 is illustrated in Fig. 3, 1) representing the dynamo supplyingcurrent to the main circuit ll, 13 the battery supplying current to thesafetycircuit S, and A A the switch device adapted, on the interruptionof the safety-circuit, to intercept communication through the mainconductor.

Throughout the line all the safety-wires c, Fig. l, are included in onecircuit S, to which current is constantly supplied by the battery 1 thiscurrent being just strong enough to retain the armature A of the switchor cutout in position for enabling the other or more powerful current totraverse the main circuit ll. \Vhen the saiety-currentis interruptcd thearmature A, being no longer attracted, falls away and instantly effectsthe interception of the main circuit it. Thus, when a cable of theimproved construction, forming the main electric line, is strained to apoint threatening it withruptnre the safetywire 0, being less ductilethan the main conductor a, breaks, interruption in the main circuit 11ensuing before the copper conductor a itself breaks.

The method of connecting a cable of the construction hereinbeforcreferred to with reference to Fig. 2 is illustrated in Fig. i. As thereare in this instance two safety-conductors c c, and consequently twosafety-circuits S S, a cut-out A is connected to each of theseconductors, current being supplied for both cut-outs by one battery 13common to both. In this arrangement upon either of the two safety-wiresc 0 being broken the current is diverted from the main conductor abeforcthe latter suffers fracture and protection afforded against sparks beingemitted on such fracture taking place.

To provide at once against both kinds of aeeidentsviz., those due toexcessive tension and those due to erushing-a cable constructed inaccordance with Fig. 1 may be combined with a special safety-switch,such as shown in Fig. 5. In this Iigure I) designates the dynamo; ll,the main circuit; S, the safety-circuit; A, the cut-out or switch; l3,:1 battery, and R a relay provided with double contacts 7" r, theprovision for affording safety coming into operation both when. thecurrent is cut off and when it is considerably intensified. The contacts0' r of the relay are clcc trically connected with one pole and thetongue .2 with the other pole of the battery 1 The safety-wire c, or, inother words, the safety-circuit S, is fed in the manner illustrated inthe drawings i. 8., by part of the tension of the main current-and bythe aid of a resistance \V the safety-current flows through the coils ofthe relay, and while its power is normal retains the tongue in theintermediate position, overcoming for the purpose the resistance of theusual relay spring, the battery-circuit being .in this position open. Ifthe cable be so far strained that it is about to break, thesafety-condimtor will in all cases break first. The relaysprin thereuponbecome released and close the circuit 13 of the battery 1 by causing thetongue to come into contact with the contact-piece r, for example, ofthe relay. The armature A is thus attracted and the main circuit IIinterrupted. Should, on the other hand, the cable be crushed anddamaged, so that a connection is established between the main conductora and the safety-coeductor c, an intensified current will pass from itthrough the safety-00nductor S, the coils of the relay will be excitedto a greater extent, and the tongue .2 will meet the contact '7", thebattery-circuit l3 thereupon becoming closed, the armature A attracted,and the main. circuit H interrupted, as before.

hat I claim as my invention, and desire to secure by Letters Patent, is-

1. An electric cable comprising a main conductor and asafety-coiuluctor, the latter be ing of such a character as to withstandless tensile strain than the main conductor; so that upon thesafety-conductor breaking the current is, by means of suitable switchapparatus, diverted from the main conductor, before the latter breaks,substantially ashcrein described.

2. An electric cable comprising a main conductor and a safety-conductor,the latter being arranged in such a manner that upon its being forcedinto contact with the main conductor, the current is, by means ofsuitable switch apparatus, diverted from the main conductor,substantially as herein described.

0. An electric cable comprisin two or more main conductors and two ormore safety-con- ICO from those conductors before the latter break,substantially as herein described.

4:. The combination, with an electric cable comprising a main conductorand a safetyconductor conveying independent currents, of a switch A, arelay R, and a resistance W, arranged or operating substantially asdescribed and whereby, on the safety-conductor being either broken orcrushed into contact with the main conductor, the current 10 conveyed bythe main conductor is instantly interrupted.

THEODORE GUILLEAUME. Vitnesses FRITZ SoHRoDER, SOPHIE NAGEL.

